Detection of Cryptosporidium oocysts in bivalve molluscs destined for human consumption.
Between November 1998 and March 1999, 17 samples of clams (Dosinia exoleta, Ruditapes philippinarum, Venerupis pullastra, Venerupis rhomboideus, Venus verrucosa), 15 of mussels (Mytilus galloprovincialis), and 6 of oysters (Ostrea edulis) were tested for the presence of Cryptosporidium sp. oocysts using various stain techniques and a commercially available kit containing fluorescein isothiocyanate-conjugated monoclonal antibodies. Each sample consisted of 12 individuals. All molluscs were harvested in northwest Spain (Galicia) except for R. philippinarum, which was from Italy, and one of the 6 oyster samples, which was from England (UK); all were from populations destined for human consumption. Cryptosporidium sp. oocysts were found in 21 of the 38 samples (55.2%): the single samples of V. verrucosa and D. exoleta were infected, as were 5 of 8 samples of R. philippinarum, 3 of 6 of V. pullastra, 6 of 15 of M. galloprovincialis and 5 of 6 of O. edulis (including the English sample).